High-voltage foam breaker



Sept. 2s, 1.948. I, NK 2,450,016

HIGH VOLTAGE FOAM BREAKER Filed Oct. 12, 1944 3 Sheets-Sheet 1 Sept. 28,1948. l. PINKEL 2,450,016

HIGH VOLTAGE FOAM BREAKER Filed Oct. 12, 1944 s Sheets- Sheet 2 5 sex513 4 a. $4

FOAM FLOW PATH 3&

FIG. 2

gvwe/wbdv a "1. IRVING PINKEL 5 l 1948. PINKEL HIGH VOLTAGE FOAM BREAKER3 Sheets-Sheet 5 Filed Oct. 12, I944 FIG. 3

grwc/wbo'v IRVING PINKEL Patented Sept. 28, 1948 UNITED STATES PATENTOFFICE HIGH-VOLTAGE FOAM BREAKER Isadore Irving Pinkel, Cleveland, OhioApplication October 12, 1944, Serial No. 558,445

I 40mins. (01204-302) (Granted under the act of March a, 1883, as

amended April so, 1928; 370 0. G. 757) This invention relates foam fromliquids and, in particular, to apparatus employing an' electrical fieldwithin which foam from oil or the like is directed to P 50. that gasentrained therein,-as bubbles, is caused.

to be released therefrom by reason of the creation of a brush discharge.involving the handling or distribution of various typ s ofliquids,foaming usually takes place due to air or other gases present becomingentrained therein thus affecting the efliciency of the systems. Where adistillation process is'involved, foaming oithe distillate not onlylowers thedistillation efliciency but very often results in a carryoverof the charge-stock into the distillate receiver. n

The invention as defined and claimed herein is shown incombination withan aircraft engine oil system of the dry-sump type, in Whichthe oilsupply is carried in an oil tank and circulated to and from the engineby pumps. The foam, which is invariably produced in the oil tank byreason of the gases from the crank case mixing with and circulatingtogether with the oil pumped from the engine, reduces the elficiency ofthe oil circulating pressure pump and otherwise greatly disturbsoperation of the lubricating system. The reduction in the pressure pumpefliciency caused by the oil tank foambecomes more and-more acute withaltitude of flight and may impose a maximum flight altitude appreciablybelow that for which the aircraft isdesigned For thisreason and also dueto the fact that a. considerable amount of oilislost to. the atmospherewhen oil foam ,fills to overflowing the tank and enginecrankcase,the;cruising range of the aircraft may be materiallyreduced,so that the Problem of oil foam formation in aircraft oilsystems is ofyital importance. g

-One object of this invention is to provide a foam breaker which ispositive in operation and conducive to a rapid flow and processing ofthe liquid and foam passing therethrough;

.Another object of this invention is to provide afoam breaker whichrequires very. little eifort to operate, is readily adapted tovariousapplica tions, is simple in construction and light in I 7 These as wellas the various;othe r novelfeatures and advantages of this inventionwill become apparentfrom a reading, of the specification andaccompanying drawings of which:

Fig. 1 is a cross-sectional view of the foam breaker-and oil tank withinwhichitis secured; Fig. 2 is a cross-sectional view'of an alternate formof the foam breaker incorporating a multis plicity of foam breakingelectrodes; and,

to apparatus for clearing In many processes a 2 Fig. 3 is across-sectional view of the modified form of the foam breaker and oiltank in which it is secured, for use with foams that are conduc-. torsof electricity. I With reference to Fig. 1, there is disclosed an" oiltank I 0, having firmly secured therein but; electrically insulatedtherefrom an oil-foam breaker, indicated generally bynumeral -Il, oilinlet pipe l2, funnel I3 through which oil passes in flowing from theoil-foam breaker ll'tothe. lower part of the tank I0, and exhaust memberI4 for venting the released gases from the tankJI Th oil inlet pipe I 2,for delivering oil to the breaker II, passes through suitably sealedopen-. ings Ho and |3a in the sides of tank I0 and fun-T nel I3respectively. a

. The oil-foam breaker I I comprises a. cup li made from a suitabledielectric material, such as plastic or the like, secured to butelectrically in-v sulated from the tank l0 by means of fasteners I6 andinsulation spacers I 1 respectively, and a cylindrical shaped doublewalled screen I 8 secured to but electrically insulated from oil inletpipe l2 by means of ring IB-so that it projects upinto the cup l5,allowing sufiicient space between the outer walls thereof and the innerWalls and top of the cup I5 to permit the free passage of, oil foamtherethrough. Imbedded in the side wallof cup I5 is a cylindrical helixof wire-or metallic tape 2| and in the base a spiral coil 2| a ofsimilar material connected electrically in series'relationship tothecoil 2|. The continuity of the electrical circuit is provided by meansof a, suit-; ably insulatedbinding post 23 joined tocoil2| and to anexternal lead wire 24a through inner connecting wire 24 and suitablyinsulated binding post 25. The lead wire 24a provides one point at whichconnection with an outside source of, high potential electrical energyis to be made. Ametallic screen I8, also formed in the shape of, acylindrical cup, consists of a base 26 having acentral opening thereinfor accommodating the securing ring l9, outer and inner verticallyextending concentric cylindrical walls 21 and 2 8, inner wall 28 beingformed integrally with the base 26, annular portions 29 and 3| securedat their edges to walls 21 and 28 respectively and short, verticallyextending cylindrical wall 32 secured to the inner edges of annularmembers 29 and 3| respectively. Screen openings in the an- :nular member3| are tightly sealed with a plastic or lik material so as to preventthe passage of liquid therethrough. To one end of b g post 33 iconnected a lead wire 20a and to the other :an inner connecting wire 20joined to screen I8, thus providing the second point at which c'onnection with an outside sourceof high potential electrical energy is to bemade. The circular opening 34, of sufficient size, is provided at thetop of screen I8 for permitting the foam, during the processingoperation, to pass readily therethrough to a source of high potentialelectrical energy to.

impress an electrical charge on each of the cupshaped members I5 and I8,the space existing between the inner surfaces of member I5 and outerwall 21 and top 29 of member I8- being; sufficient to prevent formationof an electrical arc and also to provide a sufficient clearance for the"oil foam passing therethrough so that its progress is not impeded.Carrying foam whichmay be entrained therein, oil enters through the pipeI2 and is discharged uponthe surface of thering- I9 and the screensurface 25. The oil which is free of foam will drain through theopeningsin the screen surface 25- and side walls 28; as indicated by the arrowsin Fig. 1, and proceeddown" into the funnel I3 from which it isdelivered to the bottom of tank ID. The foam remaining; however, doesnot pass through the screen but is forced rupwards through the circularopening 34 to be dispersed in a uniformly thin mass within theelectrostatic field between the cup I5' and screen I8. For the bestefficiency this electrostatic field comprising the space betweenthesurface of the inner screen 21 and the adjacent surface of cup memberI5 as well as that between outer screen surface 29 and the adjacentinner surface of cup I5, is of a s-uificient magnitude to produce abrush discharge in the foam passage. The material from which the cup I5is made is of a sufficient dielectric strength to maintain electrostaticfield stability so that electrical arcing across the passages isprevented.

An appreciable portion of the oil recovered when the foam is brokenpours through the openingsin screen 29 and down into the inside of thedouble wall of screen member I8, striking the sealed surface 28 fromwhich it is deflected down into funne1'l3 through the opening existingbetween side wall screens 21' andv 28. The remainder of the foamcontinues on its. path down through the electrostatic field formedbetween outer screen wall 2T and the adjacent inner wall of cup I5within which gases entrained therein are released. The oil, free offoam, passes downwardiy into the funnel I3 and finally to the bottom. oftank ID. The sealed screen surface 3i not. only provides drainage forthe recoveredoil but prevents the oncoming foam from making contacttherewith and being wetted thereby, the effect of which would be toincrease the oily film thickness thus rendering it more difficult tobreak thefoam. Thepossibility of reformation of, foam in the oil afterit has passed through the breaker is. reduced to a minimum, by reason ofthe inwardly converging walls of funnel I3 which direct the oil from thebreaker to the main oil tank If) inan undisturbed even flow. Gasesreleased from the foam. pass through opening 30d into the tank Ill fromwhich they are exhausted to the atmosphere through the vent I4.

Fig. 2 shows an alternate form of the foam breaker incorporating amultiplicity of foam breaking electrodes. Oil tank 42 has securedtherein, but electrically insulated therefrom, an

oil-foam breaker indicated generally by numeral 55, oil inlet pipe 4|,and gas vent 43. The oil inlet pipe passes through suitably sealedopenings 4Ia in oil tank 42.

The oil-foam breaker 55 contains a central electrode 54' andcylindricalshell electrodes 52, 52a, 52b, 52c, 53, 53a and 53bsubstantially coaxial with electrode 54. Each of the cylindrical shell,electrodes 53, 53a, and 53b is located between two cylindrical shellelectrodes of the set 52, 52a, 52band 52c, and are substantially equallyspaced therefrom to form annular flow passages of nearly uniform width.Cylindrical shell elec trodes, 53, 53a, 53b, and solid cylindricalelectrode 54 are supported by and securely fastened to. metallic-rod 49*ina manner to establish electrical contact between metallic rod 49 andsaid cylindrical electrodes. The second set of cylindrical shellelectrodes 52, 52a, 52b and 52:: are suspended from and: securelyfastened to metallic rod in a manner to establish electrical contactbetween said metallic rod and said: cyiindri calshell electrodes. Eachelectrode of the second set 52, 52a, 52b and 520, is fitted withacoverof dielectric material 58, 5.8a, 58b and 580 rye-s spectively. inthe region of the annui-ar foam flow.

passage which provides a uniform thickness ofelectricalinsulationaround, the electrode onboth nected to end of metallic-rod 49 at 49a.

the inside and" outside surfaces andacross one end thereof. Metallic rod49' is supported by. insulator sleeves 4'8 and 51. extending throughsealed openings 48a and 51a respectively in oil tank 42. Metallic rod45- is supported atits ends by insulator sleeves 44 and 56 extendingthrough sea-led openings 44a and: 56a, respectively in' oil tank 42.Lead wire 4'6 is connected to end of metallic rod 45- at 45c, and leadwire 47' is con-. Lead wires 45' and 41 are the two points to which areconnected the terminals of a source of high difference of electricalpotential energy. Spacer- 65; made of dielectric material, is cementedto the inside wall of oil tank 42 and occupies the tank space betweenthe outside surface of electrode'insulator 58c and the inside wail ofsaid oil tank.

The operation of the device is carried out as follows: I

The two lead wires 46 and-41- are connected to a source of highpotential electrical energy to establish a strong electrical fieldacross the annular foam flow passages between the electrodes of the; set53, 53a, 53b and 54, and the electrodes of the set 52', 52a, 52b and520. Oil-bearing foam flows into 011 tank 42 through-inlet'pipe 4i andaccumulates above the oil level 50 in oil tank space 5|. At the level ofthe foam breaker 55 the accumulated foam must fiow into the foam flowpassages where the foam is broken in the electric field; The efficiencyof the foam breaker is increased if the electric field in the foam flowpassages is strong enough to produce a brush dis charge. The oil that isrecovered from the foam channels-down through the foam layer in the oiltank to theoil level 50. The gas released from the foam is vented fromthe tank through gas vent 43. Although the electrodes 52, 52a, 52b, 52c,53,5301, 5311 and 54 are shown as cylindrical coaxial elements, it isobvious that flat plate electrodes or electrodes of other shapes mayalso-be used. I

For breaking-foams that are *conductorsof' electricity the arrangementof the electrodes shown in Fig. 31s effective. Withrefemnce to 3 thereis shown in oil tank I2 in which is mounted and insulated electricallyfrom said tank an insulated electrode 80 positioned above the oil level82, an exposed electrode 8| immersed in the tank oil, an oil inlet pipeH, and a tank gas vent 13. The oil inlet pipe passes through a suitablysealed opening Ha in the wall of oil tank 12.

The foam breaker comprises the exposed electrode 8| extending throughinsulator sleeve 93 into the tank oil, :and the insulated electrode 80mounted above the oil level 82 in oil tank 12. Electrode 88 is embeddedin a disk of suitable dielectric material 11 which is supported from thetop of oil tank 12 by screw 84 extending through opening 85 in top oftank 12 into threaded hole 83 in boss 86 which is integral with disk 11.Disk 11 extends over the entire cross-section of oil tank 12 so thatfoam cannot flow by the perimeter of said electrode and enter into thetank space above said electrode. Connecting wire 16 makes electricalcontact with wire 92 and metallic plate 88 through hole 8! in disk 11.Insulator sleeve 14 is mounted in opening 14a of the side Wall of oiltank 12 in a manner to be leakproof, and insulates wire 92 fromelectrical contact with oil tank 12. Lead wire 15 is electricallyconnected to wire 92 and lead wire 88 is electrically connected toelectrode 8|. Electrode 8| is insulated from oil tank 12 by means ofinsulator sleeve 93. Lead wires 75 and 88 are the two points to whichare attached the terminals of a source of high difference of potentialelectrica] energy. Holes 19 and 19a extend through dielectric material17 to provide a passage for gases released from the foam to flow to theoil tank vent line 13.

The manner of operation of this modified device is as follows:

Oil-bearing foam enters oil tank 12 through oil inlet pipe H. The foamfloats on top of the oil level 82 where it accumulates in the foam space89. By virtue of the electrical conductivity of the oil and oil foam,due to the presence of moisture plus soluble metallic salt or acids, thefoam has the same electrical potential as that which is impressed onelectrode 8|. As foam level 80 approaches electrode 88 the intensity ofthe electric field in the intervening space 9| increases up to the pointwhere the foam breaking at foam level 98 proceeds at the same rate foamis introduced into tank 12, at which time no further rise in the foamlevel occurs. The gas released from the foam passes through openings 19and 19a and passes out through gas vent '13. The oil recovered from thefoam channels down through foam layer 89 to the oil level 82.

It will be understood that the above description and accompanyingdrawings comprehend only the general and preferred embodiment of theinvention and that various changes in construction, proportion andarrangement of the parts may be made within the scope of the appendedclaims without sacrificing any of the advantages of the invention.

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

I claim:

1. An apparatus for releasing gases entrained as foam in liquids, saidapparatus comprising: a tank; a pair of electrodes having their surfacesuniformly spaced apart and mounted within and electrically insulatedfrom said tank and from each other to form a foam flow passagetherebetween; an insulating covering on one of said electrodes over allof the surface of said electrode in contact with the atmosphere of thefoam flow passage; a porous member Within said tank and adjacent saidelectrodes; an electrical conductor connected to each of said electrodesand adapted to be connected to a source of high potential electricalenergy; an inlet conduit adjacent said porous member positioned todirect foam carrying liquid to said member to permit the portion of theincoming liquid which is free of foam to pass through said member andthe remaining foam to flow into said passage; and means for directingall of the foam free liquid into the bottom of said tank.

2. In an apparatus for releasing gases entrained as foams in liquids,the combination comprising: a tank, a pair of electrodes mounted withinsaid tank and having their surfaces uniformly spaced apart to form afoam flow passage therebetween; a porous member within said tank andadjacent said electrodes; an electrical conductor connected to each ofsaid electrodes and adapted to be connected to a source of highpotential electrical energy for impressing a large difference ofpotential across said electrodes; an inlet conduit adjacent said porousmember positioned to direct foam carrying liquid to said member topermit the portion of the incoming liquid which is free of foam to passthrough said member and the remaining foam to flow into said passagewherein the gas entrained therein will be released; and means forreceiving said portion of the liquid and the liquid from which gasesentrained therein have been released.

3. In an apparatus for releasing gases entrained in liquids as foam, thecombination comprising: a pair of extended surface electrodes eachhaving a portion thereof uniformly spaced apart from the other to form afoam flow passage therebetween, another portion of one of saidelectrodes being porous to permit the drainage therethrough of that partof the liquid initially free from foam; a separate electrical conductorconnected to each of said electrodes adapted to be connected to a sourceof high potential electrical energy; an inlet conduit adjacent theporous portion positioned to direct foam carrying liquid to said porousportion; and means for receiving said liquid initially free from foamand the liquid from which gases entrained therein have been released.

4. The combination according to claim 3 wherein said electrodes arecylindrical in shape one being placed concentrically within the other.

I. IRVING PINKEL.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,170,184 Peek Feb. 1, 19161,430,302 Harris Sept. 26, 1922 2,083,802 Woelflin June 15, 19372,108,030 Darrah Feb. 8, 1938 2,240,495 Dillon et al. May 6, 19412,364,118 Wolfe Dec. 5, 1944 OTHER REFERENCES Electrical Phenomena inGases, (book), by Darrow, published in 1932 by Williams & Wilkins 00.,page 443.

